A study of equivalence between adaptive learning and loop shaping methods for disturbance compensation

作者：Yabui Shota^*; Okuyama Atushi; Atsumi Takenori; Kajiwara Itsuro

来源：Journal of Advanced Mechanical Design, Systems and Manufacturing, 2014, 8(3): 13-00198.

DOI：10.1299/jamdsm.2014jamdsm0016

• Disturbance compensation
• Periodic disturbance
• Non-periodic disturbance
• Adaptive feed-forward cancellation
• Resonant filter
• Hard disk drive

This paper introduces a theoretical analysis of the disturbance compensation methods in positioning systems. There are two major methods used to compensate for disturbances. The first one is based on a loop shaping method and the second one is based on an adaptive learning method. We make a comparison between a resonant filter used as the loop shaping method and an enhanced adaptive feed-forward cancellation (AFC) method used as the adaptive learning method. To compensate disturbances, the resonant filter decreases the gain of the sensitivity function at the disturbance frequency by using the vector locus. The adaptive learning method adjusts the coefficients of the enhanced AFC to compensate for a disturbance. We found that the LTI model of an enhanced AFC is the same as that for a resonant filter when we compared their characteristics. A simulation of the disturbance compensation in a hard disk drive showed that these time responses and frequency responses coincided. Moreover, the results showed advantages of each of the control methods with the exception of the performance. A resonant filter realizes low cost implementation with compare to an enhanced AFC. That is, a resonant filter easier to implement than an enhanced AFC. An enhanced AFC has the utility to realize a high quality function control system simultaneously able to compensate and estimate for disturbances. The results of the evaluation in this study will provide design engineers with guidelines for selecting an optimum control strategy in actual applications.

• 出版日期2014